Feeding mechanism for sewing machines



Oct. 25, 1932. F. F. zElr-:R 1,884,488

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FEDING MECHANSM FOR SEWING MACHINES Filed Sept. 6, 1928 5 Sheets-Sheet 2 r mug. J9 2l f" A v 0 7/16 [lin -f'9 Uf 1f 1 15g J7 "J7 36 33 g I J 9 JJ* JJ,

Oct. 25, 1932. F. F. zExER FEEDING MECHANISM FOR SEWING MACHINES 5 Sheets-Sheet 3 Filed Sept. 6, 1928 Ocf.25, 1932. F. F. ZEIER 1,884,488

FEEDING MECHANISM FOR SEWING MACHINES Filed Sept. 6, 1928 5 Sheets-Sheet 4 l A .-.J

oct. 25,1932. F. F. zE-IER 1,884,488

FEEDING MECHANISM FOR SEWING MACHINES Filed sept. e, 1928 5 sheets-sheer 5 Patented Oct. 25, 1932 UNITED STATES PATENT FFICE FREDERICK F. ZEIER, OF CHICAGO, ILLINOIS, ASSIGNOR T UNIN SPECIAL MACHINE COMPANY, OF CHICAGO, ILLINOIS, A CQRPORATION OF ILLINQIS FEEDING MECHNISM FOR SERVING MACHINES Application filed September 6, 1928. Serial No. 304,331.

The invention relates to new and useful improvements in feeding mechanisms for sewing machines, and more particularly to a feeding mechanism which includes a fourmotion feed dog.

An object of the invention is to provide a feeding mechanism having a main feed dog and an auxiliary feed dog with devices for giving a. differential movementJ to said feed dogs which are positively connected and free from sliding adjustments.

A further' object of the invention is to provide-a feeding mechanismof the above type wherein both feed dogs are moved back and forth from a feed rocker and wherein the feed bar carrying one of the feed dogs is pivoted to the feed rocker, and wherein the feed bar carrying the other feed dog has a connection to the feed rocker which includes a flexible member.

A further object of the invention is to provide a feeding mechanism of the above type wherein means is provided for varying the extent of the differential movement imparted to the feed dogs7 which means is free from sliding connections.

A further object of the invention is to provide a feeding mechanism which includes a main feed dog and a feed bar on which said main feed dog is mounted with devices for raising and lowering the feed dog which include an eccentric strap, an eccentric, and a floating sleeve disposed between the eccentric and the eccentric strap.

These and other objects will in part be obvious and will in part be hereinafter more fully disclosed.

In the drawings: Y

Fig. l is a top plan view of the bed of the machine with the cloth plate, throat plate and overhanging arm removed, and with certain parts broken away to more clearly show the feeding mechanism. Y

Fig. 2 is an end View of the machine with certain parts in section and certain parts broken'away to showthe connection at the end of the main shaft for imparting feeding movements to the feed dogs.

Fig. 3 is a view of a portion of the machine from the rear with certain parts omitted so as to show more clearly the feed rocker and the devices directly associated therewith for imparting movements to the feed bars.

Fig. d is a sectional view taken on the line 4 4 cf Fig. l.

Fig. 5 is a sectional view taken on the line 5--5 of F ig. l, and showing the feed dogs at the rear end of their stroke.

Fig. 6 is a view similar to Fig. 5, but howing the feed dogs at the beginning of neir feed stroke.

Jsig. 7 is a sectional view on the line 7 7 of F ig. l, showing the shifting means for the differential feed adjustment.

Fig. 8 is a side elevation partly in section, showing the devices for raising and lowering the feed dogs.

Fig. 9 is a sectional view on the line 9 9 Y of Fig. 8.

Fig. 10 is a sectional view through the eccentric strap with the eccentric and floating sleeve removed.

Fig. ll is a detached sectional view through the floating sleeve.

Fig. l2 is a diagrammatic view showing the operation of the differential feeding mechanism.

The invention is directed to a feeding mechanism for sewing machines `and as illustrated includes a main feed dog carried by a feed bar located beneath the plane of the throat plate, and an auxiliary feed dog mounted on a feed bar which is supported so as to move up and down with the main feed bar. The main feed bar is pivoted to a feed Vrocker which is oscillated by suitable connections on the main shaft. Mounted on the feed rocker is a bell crank. Said bell crank is free to oscillate on the rocker and moves bodily with the rocker. This bell crank is connected by a flexible connection to the auxiliary feed bar. rIhe other end of the bell crank is connected through a link with a crank arm that may be shifted to various set positions. As the feed rocker oscillates this bell crank is moved bodily therewith and will be given an additional movement depending upon the set position of the crank. The feed bars are raised and lowered-by an eccentric strap locatedY directly beneath the free end of the main feed bar.

The main shaft extends beneath the feed bar and carries an eccentric which cooperates with the eccentric strap. Surrounding the eccentric in the eccentric strap is a. floating sleeve, which, not only more efficiently lubricates the moving parts, but also dis tributes the wear thereon.

Referring more in detail to the drawings, the invention is shown as embodied in a sewing machine having a bed 1. This bed 1 is also formed with a supporting structure 2 on which the overhanging arm is de'tachably mounted. The bed is further provided with suitableV bearings in which the main actuating shaft 3 rotates. The looper rocker 4 carries the loopers and this looper rocker is oscillated through suitable connections with the main shaft 3. The loopers are oscillated on the looper rocker by means of a link Also mounted on the bed a throat plate. support 6. These features form no part of the present invention which is directed more particularly to the feedingl mechanism.

The over-hanging arm which is preferably used with the illust-rated type of supporting bed and feeding mechanism shown described and claimed in my Letters Patent No. 1,843,188, granted February 2, 1932.

The feeding mechanisiu includes a main feed dog 7 and an auxiliary feed dog 8. The main feed dog 7 carried by a feed bar 9. This feed bar 9 is pivotcd to a feed rocker 11. The feed rocker 11 is mounted on a shaft 12, which in turn is mounted for free oscillation in supporting lugs 13, 13 carried by the bed of the machine. The shaft held from endwise movement by coliars 14, 14 attached to the respective ends of the shaft. The feed bar 9 is provided with a forked arm at its rear end, and this forked arm carries collars 15, 15. A rod 16 passing through the feed rocker 11 and through the collars 15, 15 forms the connection between the feed bar 9 and the feed rocker.

Mounted on this rod 16 is a bell crank 17. The bell crank 17 is free to oscillate on the rod V16 and will move bodily with the rod 16 when the feed rocker is oscillated. The auxiliary feed dog 8 is mounted on an auxiliary feed bar 18. This auxiliary feed .bar is, in turn, mounted in a recess formed in the side face of the main feed bar 9. This recess is closed by a cover plate secured to the main feed bar and thus it is that the auxiliary feed bar is mounted on the main feed bar so that it will move up and down therewith but is free to move endwise on the main feed bar independent of the main feed bar movements.

This auxiliary feed bar 18 is connected to the bell crank 17 by a steel strip 19 which vis very flexible. A screw 20 passes through a clamping block and through one end of the steel strip into the upper end of the bell crank 17. A screw 21 passes through a clamping block and also through the end of the steel strip into the upper face of the rear end of the auxiliary feed bar. This bell crank 17 has a vertically extending arm and also a horizontally extending arm 17a. The arm 17 a is pivoted at 22 to a link 23. The link 23 is freely connected to a crank 24 on an arm 25 carried by a shaft 26. This shaft 26 is mounted for free oscillation in a bracket 27. A coil spring 28 encircles the shaft 26 and one end of this spring bears against the face of the bracket 27 while the other end of the spring is connected to a pin 29 carried by a projecting arm mounted on a collar 30. The collar 30 is clamped to the shaft 26. This spring coiled about the shaft tends to turn the shaft in ya counterclockwise direction as viewed in Figs. and 6. This will tend to rotate the crank pin 24 in an arc about the center of the shaft 26 and in a counter-clockwise direction.

The link 23 permits this shifting of the shaft 26 without necessitating any connections to be loosened or any sliding connections. This makes a positive connection which cannot work loose when the shaft 26 is held in a set position. The bracket 27 is secured to the bed by suitable bolts 31, 3l.

The feed rocker is oscillated by means of an arm 32. This arm is provided with a collar 33 which is secured to the end of the rod 16. The arm is clamped to this rod 16. The end of the arm 32 is pivotcd at 34 to a link 35. This link 35 is, in turn, connected to a crank 36 which is mounted on a disc 37 carried by the main actuating shaft 3. An adjusting screw 38 is provided for shifting the position of the crank to vary the throw imparted to the feed rocker. By loosening the slip collar and shifting the arm 32 on the rod 16 the working position of the feed rocker may be varied and this, of course, will vary the working position of the main feed dog; through this adjustment the feed dog may be seteither closer to or farther from the needle in its cycle of movement. 1t is understood that the rod 16 is secured firmly to the feed rocker by means of set screws 39, 39. The bell crank and the collars on the main feed bar fill the space between the arms of the feed rocker so that they are held from endmovement thereon as Clearly shown in Fig. 3.

The feed bars are raised and lowered by an eccentric 40 carried by the mainactuating shaft 3. This main actuating shaft 3 extends beneath the forward end of the feed bars. The main feed bar has a depending bracket arm 41 which is preferably formed integral therewith. The eccentric 4() is secured to the main shaft by means of a spot screw 42. Surrounding the eccentric is a floating sleeve 43 and this floating sleeve 43 closely lits an opening in an eccentric strap rssaea's 4A. The eccentricstrap 44- is provided with forked arms which straddle the end of the depending bracket arm ll.y A pivot rod e6 extends through the arms of the eccentric strap and also through the free end of the bracket arm il and is secured to the bracket arm ll by means of a clamping screw e?. Tn Fig. l0 the eccentricstrap is shown sectioned and it will be noted that on the inner face of this eccentric strap there are grooves i8 which aid in thedistributing of the lubricant. y

Y The floating sleeve as shown in 1l is provided .with an annular groove 49 midway between` the ends thereof. A screw 50 is threaded into the eccentric strap and this screw 50 is provided with a projecting portion 5l which enters the annular groove 49 andprevents the floating sleeve from moving endwise in the eccentric strap while at the same time vit permits said floating sleeve to rotate freely in the strap. Said oating sleeve is formed with openings 52 through which the lubricant may pass from one place in the sleeve to another. The eccentric strap is yprovided with a pocket 53 in which an oil pad' 54 Vis placed. Oil is supplied to the oil pad through a suitable opening 55 leading to the outer face of the strap and the lubricating oil flows through a passage to the outer face of the floating sleeve.

From the above it will be apparent that a feeding mechanism has been provided. wherein the feed dogs are positivelyT raised and loweredv by an eccentric operating through anr eccentric strap which is connected to a bracket" arm carried by the main feed bar. This structure together with the Vfloating sleeve which distributes thewear and insures proper lubrication contributes to a very high speedv machine and one wherein the movements imparted to the feed dogs will be uniform at all speeds. It will also be noted that the `feedgbars are moved back and forth by connections with the feed rocker which free from sliding adjustments and which are positive in their connection Vso that the feed dogs when set for a' given operation may be operated at very high speed and a uniform movement given to said feed dogs without any overthrow for all speeds.

lVhen it is desired to vary the differential movement imparted to the feed dogs the shaft 26 is oscillated to vary the set position of 7' the crank 24. On the end of the shaft 26 is a collar 57. This collar is clamped to the end of the'shaft. The collar is provided with a radially projecting lug or finger 58. lilount ed on the bracket 27 is a lever 59. Said lever is pivoted at to the bracket. This lever is provided with an upwardly projecting` finger or lug 61. As clearly shown in Fig. this upwardly projecting linger or lug Gl lies directlybehind the downwardly projecting linger 'orlug 58 on the collar 5l'. lllhen the lever 59 is moved downwardly from the plosition shown'in 7 it will rotate the shaft 26 in a counterclockwise direction as viewed in lthis ligure andthis, of course, will move the crank pin 24.- y in al clockwise direction as viewed in Figs. 5 and 6. A suitable flexible connection not shown is attached to the end of the l Jer and to either a knee shift or tieadle for pulling down on the lever. The lever 59 lies alono'side of a bracket G2 secured to the bed of the machine by suitable bolts 63. The lever is provided with pin 64. f The outer face of this bracket G2 is curvedv about tli `votalfp rt of the lever as the center and,-therefore, thepin 6a will move along outer of the bracket. TheA outer ace of l. e bracket is provided with a scale l lng marks as clearly shown in Fig.

inc icates the set position of the vliend also indicates the character of Jthe differential feed accomplished by such set position of the lever.

he braclnetv o2 slotted as shown in F ig.

` are two stops G5 and 66. These stops are c )able of being shifted in the slot to *.fariou.J s positions and are secured in their set positi ns by suitable clamping means. stops may be set, if desired, so tl the lever 59 when against the lowerstop will position the orankfor the maximum differential throw desired. On the other hand w "u the lever is moved so as to contact wie other stop a different de- `ow may be obtained or 7. alcun-teil in the slot sired differei i I the crank may be set so that the feed dogs will nieve substantially in unison.l Tt will also be noted tha f steps may be adjusted 59 inl a set position; drawings, there has been vninatically the feed rocker, ...id the link cornected to the bell crank the crank plvl-Uien the parts are in tle full line position, then the shaft 26 is shifte i so is to impart a maximum throw to the a friliary feed dog. The pivotal connection between the main feed bar and the feed rocker and between the bell crank and the feed rocker are in alignment. This pivotal correction is at the position inf a, when the main feed dog is at the forward ofv its stroke. The same parts are at thev posi-ion Z2 when kthe main feed dog is at tlie rear end of its stroke. The li' k Q3 oscillates about the crank pin Q4 and moves from u e position indicated at c to the position indicted at d. The are movement of the r end of the link from ln F ig. i2 of the illustrated c' the bell cra4 isa' Ethan the movement from a to b, and, therefle, the auxiliary feed bar is given a. greatgr movement than the main feed bar. In other words, the bell crank has a bodily movement with the feed rocker and is also oscillted during its bodily movements so as to increase the throw which the bell crank imparts t0 the auxiliary feed bar. When the crank pin is shifted so as to position the link 23 substantially vertical as indicated by the brkll lines in Fig. 12, then the upper end of the link 23 will move from the position indicted at g to the position indicated at d. ylhs .this end of the link 28 moves from g to d it is substantially a horizontal movement parallel with the movement of the pivotal supporting connection between thc bell crank and the feed rocker, and, therefore, the bell crank will not be oscillated to any appreciable extent in its bodily movement. The connection between the auxiliary feed bar and the bell crank under these conditions n10-ves from a point h to the point f. In this diagrammatic view there has been illustrated a iven throw of the main feed dog and also ieated the maximum differential feed threw (if vthe auxiliary feed dog and the minimum dierential throw of the auxiliary feed dog. The crank pin 24 can, of course, be set at any position between the positions indi- Olted in the full lines and broken lines in Fig. 12 and thus a different extent of differentlal movement imparted to the feed dogs. It will be understood, of course, that the lever 59 may be shifted without stopping the stitching mechanism, and thus the extent of dierential throw imparted to the auxiliary feed dog varied during the stitching of an article.

It is obvious from certain aspects of the inventin that the means for raising and lowering the feed bars may be used in connection with a single feed bar. It is also obvious that minor changes in the details of construction andthe arrangement of the parts may be made without departing from the spirit of the invention as set forth in the appended claims.

Having fully described my invention what I claim as new and desire to secure by Letters Patent, is:

Y 1. A feeding mechanism for Vsewing machines comprising a feed rocker, a main feed bar pivoted thereto, a main feed dog mounted on said feed bar, an auxiliary feed bar mounted to slide on said main feed bar, an auxiliary feed dog mounted on said auxiliary feed bar, means for raising and lowering the feed bars, and devices moving with the feed rocker and including a flexible member connected to the auxiliary feed bar for imparting a. differential movement to the auxiliary feed d 2. A feeding mechanism for sewing machines, comprising a feed rocker, a main feed bar pivoted thereto, a main feed dog mounted on said feed bar, an auxiliary feed bar, an auxiliary feed dog mounted on said auxiliary feed bar, means for raising and lowering the feed bars, a member freely mounted on said feed rocker and moving therewith, a. flexible connection between said member and said auxiliary feed bar, and devices connected to said member for oscillating said member on said feed rocker during the movements of the feed rocker.

3. A feeding mechanism for sewing machines comprising a feed rocker, a main feed bar pivoted thereto, a main feed dog mounted on said feed bar, an auxiliary feed bar, an auxiliary feed dog mounted on said auxiliary feed bar, means for raising and lowering the feed bars, a member freely mounted on said feed rocker and moving therewith, a flexible connection between said member and said auxiliary feed bar, devices connected to said member for oscillating said member on said feed rocker during the movements of the feed rocker, and means whereby the extent of oscillation imparted to said member may be varied.

4. A feeding mechanism for sewing machines comprising a feed rocker, a main feed bar pivoted thereto, a main feed dog mounted on said feed bar, an auxiliary feed bar, an auxiliary feed dog mounted on said auxiliary feed bar, means for raising and lowering the feed bars, a member freely mounted on said feed rocker and moving therewith, a flexible strip rigidly connected to said member and rigidly connected to said auxiliary feed bar, and devices connected to said member for oscillating said member Yon said feed rocker during the movements of the feed rocker.

5. A feeding mechanism for sewing machines comprising a feed rocker, a main feed bar pivoted thereto, a main feed dog mounted on said feed bar, an auxiliary feed bar, an auxiliary feed dog mounted on said auxiliary feed bar, means for raising and lowering the feed bars, a member freely mounted on said feed rocker and moving therewith, a flexible strip rigidly connected to said member and rigidly connected to said auxiliary feed bar, devices connected to said member for oscillating said member on said feed rocker during the movements of the feed rocker, and means for varying the extent of oscillation imparted to said member.

6. A feeding mechanism for sewing machines comprising a feed rocker, a main feed bar pivoted thereto, a main feed dog mounted on said feed bar, an auxiliary feed bar, an auxiliary feed dog mounted on said auxiliary feed bar, means for raising and lowering the feed bars, a bell crank freely mounted on said feed rocker and moving therewith, a flexible connection between one arm of the bell crank and said auxiliary feed bar, a link connected to the other arm of said bell crank and to a stationary part of the machine whereby said bell crank is caused to oscillate through the movements of the feed rocker.

7. A feeding mechanism for sewing machines comprising a feed rocker, a main feed bar pivcted thereto, main feed dog mounted on feed bar, an auxiliary feed bar, an auxiliary feed dog mounted on said auxiliary feed bar, means for raising and lowering the feed bars, a bell crank freely mounted on said feed rocker and moving therewith, a flexible connection between one arm of the bell crank and said auxiliary feed bar, a link connected to the other arm of said bell crank and to a stationary part of the machine whereby said bell crank is caused to oscillate through the movements of the feed rocker, and means for shifting the position of said stationary connection for varying the extent of oscillation imparted to said member.

8. A feeding mechanism for sewing machines comprising a feed rocker, a main feed bar pivoted thereto, a main feed dog mounted on said feed bar, an auxiliary feed bar, an auxiliary feed dog mounted on said auxiliary feed bar, means for raising and lowering the feed bars, a bell crank freely pivoted to said feed rocker on a line coincident with the pivotal connection between the feed rocker and the main feed bar, a flexible strip rigidly connected to one arm of the bell crank and rigidly connected to the auxiliary feed bar, a shaft capable of being shifted to various set positions, a crank pin carried thereby, a link connecting said crank pin to the other arm of the bell crank, said link operating to oscillate the bell crank during the movement of the feed rocker.

9. A feeding mechanism for sewing chinescomprising a feed rocker, a main bar connected thereto, a main feed mounted on said feed bar, an auxiliary bar, an auxiliary feed dog mounted on auxiliary feed bar, means for c raising mafeed oog feed said and lowering the feed bars, and devices moving with the feed rocker for imparting a differential movement to said auxiliary feed dog including a bell crank attached to the auxiliary feed bar and mounted on the feed rocker for bodily movements therewith, and a piv-A otally supported link connected to the bell crank for imparting an oscillation to the bell crank through the bodily movements thereof with the feed rocker.

10. A feeding mechanism for sewing machines comprising a feed rocker, a main feed bar connected thereto, a main feed dog mounted on said feed bar, an auxiliary feed bar, an auxiliary feed dog mounted on said auxiliary feed bar, means for raising and lowering the feed bars, and devices moving with the feed rocker for imparting a differential movement to said auxiliary feed dog including a bell crank attached to the auxiliary feed bar and mounted on the feed rocker for bodily movements therewith, a pivotally supported link connected to the bell crank for imparting an oscillation to the bell crank through. the bodily movements thereof vwith the feed rocker, and meansfor shifting the position of the pivotal support for the link for varying the extent Vof different al movement given the auxiliary feed bar.

11. A feeding mechanism for sewing machines comprising a main feed bar, a feed rocker connected to the main feed bar, a feed do^ .arried by the main feed bar, an auxiliar j, feed bar, a feed dog carried thereby, and means for imparting a differential movement .to the auxiliary feed bar from the feed rocker including a bell crank having a bodily back and forth movement, and a link pivoted to the bell crank-and to a. stationary part of the machine for oscillating said bell crank during its bodily movements for imparting a differential movement to the auxiliary feed bar.

l2. A feeding mechanism for sewing machines comprising a main feed bar, a feed rocker connected to the main feed bar, a feed dog carried by the main feed bar, an auxiliary feed bar, a feed dog carried thereby, and means for imparting a differential movement to the auxiliary feed bar from the feed rocker including a bell crank having a bodily back and forth movement, a link pivoted to the bell crank and to a stationary part of the machine for oscillating said bell crank during its bodily movements for imparting a difierental movement to the auxiliarj,7 feed bar, and means for shifting the pivotal support of the link for varying the extent of oscillaion imparted to the bell crank.

13. A feeding mechanism for sewing machines comprising a feed rocker, a main feed bar connected thereto, a main feed dog mounted on said feed bar, an auxiliary feed bar, an auxiliary feed dog mounted on said auxiliary feed bar, means for raising and lowering the feed bars, and devices moving with the feed rocker for imparting a differential movement to said auxiliary feed dog including a link oscillated about a stationary axis by the back and forth movements of the feed bar and means for shifting the position of said axis whereby the chord of the arc described by said link may be disposed either in substantially parallel relation with the path of travel of the feed bar or in non-parallel relation therewith to vary the stroke of said auxiliary feed dog.

lil. A feeding mechanism for sewing machines comprising' a feed rocker, a feed bar ttached thereto, a feed dog carried by said feed bar, means for oscillating said feed rocker, whereby back and forth movements are imparted to said feed dog, a second feed bar, a second feed dog carried thereby, means for imparting uniform rising and falling movements to said feed bars, a device mounted on the feed rocker for bodily movement therewith, a connection between the device and the stationary part of the machine whereby the back and forth movements of the feed rocker will impart a diferential back and forth movement to said device, and a connection between said device and said second feed bar whereby the movements of seid device are im arted to said second feed bar.

n testimony whereof, I afiix my signature.

FREDERICK F. ZEIER. 

